Volume 4: The Swiss Years: Writings 1912-1914
Page122(144 of 738)

EINSTEIN ON GRAVITATION AND RELATIVITY: THE STATIC FIELD I In 1911, after having pondered on the problem of gravitation for several years, Einstein began to formulate a theory of the static gravitational field. His early ideas on the static field were published in Einstein 1911h (Vol. 3, Doc. 23), Einstein 1912c (Doc. 3), and Einstein 1912d (Doc. 4) and are characterized by two important features: the first one is the principle of equivalence, which provides the heuristics for the theory; the second is the role played by the speed of light, which is assumed to be variable and serves as a scalar potential for the gravitational field. Einstein's work led to a harsh controversy with Max Abraham, who published a rival theory at about the same time. Einstein 1912h (Doc. 8) and Einstein 1912i (Doc. 9) represent Einstein's side of this polemic. A note added in proof to Einstein 1912d (Doc. 4) and the short paper Einstein 1912e (Doc. 7) document Einstein's first steps beyond the static case. Traces of Einstein's early attempts to deal with the problem of gravitation are also found in his "Scratch Notebook" (Vol. 3, Appendix A), as well as in his correspondence of these years.[1] II The ground for Einstein's 1912 theory of the static gravitational field had been broken five years earlier when he analyzed the problem of gravitation in his review of the theory of relativity.[2] In this review Einstein for the first time formulated the hypoth- esis of the equivalence of uniformly accelerated reference frames and static homo- geneous gravitational fields, a hypothesis later to become known as the "principle of equivalence."[3] At the time he did not publish any further thoughts on how to con- struct a relativistic theory of gravitation[4] but limited himself to drawing a number of specific conclusions from this hypothesis, most notably the gravitational red shift and the bending of light rays in a gravitational field.[5] [1]For historical discussions of Einstein's theory of the static gravitational field, see Pais 1982, sec. 11, Norton 1984, Maiocchi 1985, and Cattani and De Maria 1989. [2]See Einstein 1907j (Vol. 2, Doc. 47), §§17-20, and the corrections to this paper, Einstein 1908b (Vol. 2, Doc. 49). For historical discussions of this review, see Vol. 2, the editorial note, "Einstein on the Theory of Relativity," pp. 273-274, and Miller 1992. [3]For a discussion of the relevance of Einstein's principle of equivalence to the development of general relativity, as well as for a survey of Einstein's subsequent reformulations of this principle, see Norton 1985. [4]For evidence that Einstein did have such thoughts, see his recollections in Einstein 1933 and Einstein 1979, pp. 62-66. [5]Various calculations related to the bending of light rays are also found in his "Scratch Notebook" (Vol. 3, Appendix A).